1987 Action Superstars (unlicensed) Baseball Forum

I wanted to make note of this eBay listing: https://www.ebay.com/itm/325094289062

The three cards listed have this same front as the Mattingly in this set but are tinted green, black, and blue.  The backs are the same except with a "#4" and "Colours" below the text shown for the Mattingly card here.  The back is also printed in black ink rather than blue ink.  It's possible some variation of this set exists, or they could be something else like test print cards.

Or they could have been printed last week.

I posted about these in a Don Mattingly Facebook group and a long-time collector has another set.  I can see a post he made from 2015 showing the cards so they are at least that old.  But yes, I agree it is also possible someone made them sometime between then and this set's release.